Radio communication control apparatus, radio communication method, recording medium, and program

ABSTRACT

By making the most of the master and slave roles, the master device becomes the system controller to manage the control functions of the slave devices in a piconet. For one slave device to control another slave device, the controlling slave device issues a command to the master device, which transfers the received command to the controlled slave device. Each slave device control other slave devices in a piconet without being aware of other slave devices except the master device. Consequently, commands may be exchanged between the slave devices in a piconet which is constituted by one master device and a plurality of slave devices.

TECHNICAL FIELD

[0001] The present invention relates generally to a wirelesscommunication control apparatus, a wireless communication controlmethod, a storage medium, and a program for interconnecting a pluralityof devices in a wireless manner and, more particularly, to a wirelesscommunication control apparatus, a wireless communication controlmethod, a storage medium, and a program for controlling the exchange ofdevice operating commands between the devices interconnected in awireless manner within a predetermined communication cell.

[0002] To be more specific, the present invention relates to a wirelesscommunication control apparatus, a wireless communication controlmethod, a storage medium, and a program for exchanging device operatingcommands between the devices within a piconet constituted by one masterdevice and a plurality of slave devices as with implemented by theBluetooth™ standard and, more particularly, to a wireless communicationcontrol apparatus, a wireless communication control method, a storagemedium, and a program for controlling the exchanging of device operatingcommands between the two or more slave devices which are directlyconnected only to the master device within a piconet.

BACKGROUND ART

[0003] Recently, short-distance wireless communication technologies havecome before the footlights. The wireless communicating based on thesecommunication technologies can establish the cordless communicationbetween devices and terminals, thereby simplifying the device connectionwork and, at the same time, enhancing convenience because it issubstantially unnecessary to select installation spaces of thecordlessly connected devices. The short-distance wireless communicationis expected a great deal also as the transmission media for homenetworks for example, in which it not realistic to lay network cablesbecause of their locality.

[0004] The short-distance wireless communication may be used, forexample, not only for the data transfer between a computer main frameand its peripheral devices, but also for the data exchange betweenmobile information devices, and data and audio transmission between atelephone main body, a mobile music player, and a headset, and between amain phone and its cordless headset.

[0005] Bluetooth, which is a representative example of short-distancewireless communication, is the standard for providing a wirelessconnection interface applicable to a variety of industries and operatedand managed by the Bluetooth SIG (Special Interest Group).

[0006] Bluetooth uses a global radio frequency called ISM (IndustryScience Medical) band of 2.4 GHz and provides a total data transfer rateof 1 Mbps, in which a synchronous transmission channel of 64 Kbpsavailable for telephone voice transmission and an asynchronoustransmission channel for data transmission are provided. For thesynchronous transmission channel, SCO (Synchronous Connection OrientedLink) transmitting is used for the application to line linking. For theasynchronous transmission channel, ACL (Asynchronous Connection LessLink) transmitting is used for the application to the data transmissionbased on packet exchange. The connection range of interconnected devicesbased on Bluetooth is about 10 meters, which can be extended to 100meters with the aid of an additional amplifier.

[0007] The technical specifications of Bluetooth are largely dividedinto the core and the profile. The core defines the base of the wirelessconnection provided by the Bluetooth, while the profile, in developing avariety of functions and applications on the basis of the Bluetooth coreand assembling them into equipment, is a collection of the technicalrequirements specified for each function to guarantee the mutualconnectivity between the devices.

[0008] There are two or more Bluetooth profiles and, by combining them,one application (also called a usage model (or usage) is provided.Actually, a combination of profiles providing an application isimplemented in each Bluetooth product.

[0009] For example, a variety of Bluetooth profiles are supposed, suchas the profiles for automobiles, networks, printers, audio devices, andvideo devices in addition to the profiles for mobile phones and personalcomputers, for example. For example, for a profile for remote commandercontrol for audio visual (AV) equipment, “Bluetooth AV Remote ControlProfile” (AVRCP) may be mentioned.

[0010] Originally, Bluetooth is a wireless communication technology forproviding interconnection between mobile terminals; but, obviously, thistechnology is also designed for the application to stationary equipment.For example, the wireless connection based on Bluetooth may be appliedto the connection between a main phone and its cordless handset, amobile music player and its headset, or a stereo unit (or other mediaplayers) and its speakers (or other output devices such as displaymonitors).

[0011] Application of the wireless communication based on Bluetooth tothe interconnection of devices solves the problems of theconnector-unique shapes and characteristics obliged at cable connection.In addition, because Bluetooth is a worldwide standard using a globalwireless frequency band called ISM (Industry Science Medical) band of2.4 GHz, the globalization of communication environments may be promotedwith ease.

[0012] Bluetooth provides not only one-to-one alternate connection, butalso the construction of one-to-many simplified wireless networks.Hence, the order of communication is maintained by giving the controlcapabilities to one of the devices interconnected in a Bluetoothcommunication environment. The device given with the controlcapabilities is called a “maser device,” while the other devices arecalled “slave devices.” A network in which the master device and theslave devices are in a communication state is called a “piconet.”

[0013] Within a piconet, “piconet synchronization” is provided, in whicheach Bluetooth device in the communication state has the same frequencyhopping pattern and a time slot with reference to the master device. Thetime slot is formed by each device with reference to the Bluetooth clockprovided by the master device.

[0014] Within a piconet, one master device always exists and this masterdevice carries out communication by controlling its slave devices. Inaddition, within a piconet, each packet is received only between themaster devices and each slave device, so that the slave devices cannotdirectly communicate with each other.

[0015] The maximum number of slaves which can communicate with eachother within one piconet is specified to be seven. The maximum of onemaster device and the seven slave devices can constitute Bluetoothcommunication environment in one piconet.

[0016] In the Bluetooth communication, there is a demand for executingdevice control between the slave devices. For example, if the Bluetoothcommunication is introduced in the field of audio visual (AV) equipment,a stereo unit or a media player may be defined as a master device, whilea TV receiver and a headphone as output targets or a remote commanderfor remotely operating these output devices may be defined slavedevices. Within the Bluetooth piconet like this, it would be meaninglessfor the user if the stereo unit, the master device, cannot control thetargets such as a TV receiver and a headphone and, in addition, theremote controller, a slave device, cannot performing TV tuning andvolume setting or headphone volume setting for example. However, asdescribed above, these direct communication between the slave devices isnot supported by Bluetooth.

[0017] For example, there is “AV Remote Control Profile” (AVRCP) for oneof the Bluetooth-compatible AV device control profiles. However, becauseBluetooth can originally execute communication by constituting onepiconet by one master device and two or more slave devices, this AVRCPcontrol profile is intended to realize one-to-one communication betweenthe master device and one slave device.

[0018] In order for a remote commander, a slave device, to controlanother slave device via the master device, a method may be used inwhich a mechanisms for realizing this configuration is newly defined toimplement it as a new control profile. However, if control isimplemented in which a slave device controls another slave device viathe master device by use of the new control profile, this method cannotbe applied to the existing devices based on only AV Remote ControlProfile control.

DISCLOSURE OF INVENTION

[0019] It is therefore an object of the present invention to anexcellent wireless communication apparatus, an excellent wirelesscommunication method, an excellent storage medium and an excellentprogram which are capable of preferably exchanging device operatingcommands between devices interconnected in a wireless manner.

[0020] It is another object of the present invention to provide anexcellent wireless communication apparatus, an excellent wirelesscommunication method, an excellent storage medium and an excellentprogram which are capable of preferably exchanging device operatingcommands between the devices within a piconet constituted by one masterdevice and a plurality of slave devices as that based on Bluetooth.

[0021] It is still another object of the present invention to provide anexcellent wireless communication apparatus, an excellent wirelesscommunication method, an excellent storage medium and an excellentprogram which are capable of preferably exchanging device operatingcommands between two or more slave devices which are directly connectedonly to the master device in a piconet.

[0022] It is yet another object of the present invention to provide anexcellent wireless communication apparatus, an excellent wirelesscommunication method, an excellent storage medium and an excellentprogram which are capable of preferably performing remote controlbetween the slave devices within the same piconet by use of the remotecontrol profile based on Bluetooth.

[0023] It is a different object of the present invention to provide anexcellent wireless communication apparatus, an excellent wirelesscommunication method, an excellent storage medium and an excellentprogram are capable of realizing the remote control by one slave deviceof another slave device via the master device within the piconet by useof a conventional Bluetooth control profile such as AV Remote ControlProfile.

[0024] In carrying out the invention and according to a first aspectthereof, there is provided a wireless communication control apparatus ora wireless communication control method for controlling command exchangebetween devices in a communication cell constituted by one master deviceand a plurality of slave devices, each slave device being capable ofcommunicating with only the master device including the steps of:inquiring each device in the communication cell whether each deviceoperates as a controller or a target; inquiring each device having atarget function for a command supported thereby; and managing thecommands supported by each target device.

[0025] In the communication cell to which the wireless communicationcontrol apparatus and the wireless communication control methodassociated with the first aspect of the invention, each slave device iscommunicable only with the master device and, on a predetermined controlprofile, the master device and each slave device may operate as acontroller for issuing commands and/or a target for supporting commands.

[0026] The communication cell to which the wireless communicationcontrol apparatus and the wireless communication control methodassociated with the first aspect of the invention may be applied to adevice which becomes the master in the above-mentioned communicationcell to preferably yield the effects of the invention. The master deviceitself functions as both controller and target on a predeterminedprofile. The above-mentioned support command managing means or stepmanages the support commands of the master device itself.

[0027] According to the wireless communication control apparatus and thewireless communication control method associated with the first aspectof the invention, the master device becomes the system controller tomanage the control function namely the support commands of each slavedevice operating as a target in the communication cell. For one slavedevice operating as the controller in the communication cell to controlanother slave device, the controlling slave device issues commands withthis master device as a target. The master device which is thecontroller may transfer commands to the target which supports thecommands, namely this another slave device.

[0028] Consequently, if each slave device functions as the controller ona predetermined profile, one slave device may issue commands to anytarget in the communication cell without being aware of the existence ofthe other devices than the master device. Likewise, each slave deviceoperating as a target on a predetermined profile may only execute thecommands transmitted from the master device without being aware of theother devices other than the master device (namely, without being awareof whether each received command is from another slave device whichfunctions as the controller).

[0029] In other words, the slave device operating as the controllertransmits commands to the master device as a target and the other slavedevices operating as targets may only process the commands received fromthe master device. Namely, according to the wireless communicationcontrol apparatus and the wireless communication control methodassociated with the first aspect of the invention, control between theslave devices is realized via the master device in the communicationcell in which each slave devices is communicable only with the masterdevice.

[0030] The wireless communication control apparatus and the wirelesscommunication control method associated with the first aspect of theinvention of the invention may also include the means or step forreceiving commands from the controller in the above-mentionedcommunication cell and the means and step for processing the receivedcommands.

[0031] The command processing means or step inquires the above-mentionedsupport command managing means to transfer the received commands to thetargets which support these commands.

[0032] In addition, the above-mentioned command processing means or stepinquires the above-mentioned support command managing means to cause themaster device itself to execute the received commands if these commandsare supported by the master device in which the wireless communicationcontrol apparatus or the wireless communication control methodassociated with the first aspect of the invention is implemented.

[0033] If there are two or more targets which support the receivedcommands in the communication cell, the controller device from whichcommands are transmitted may have a function of specifying a particulartarget device as a device for command execution.

[0034] Alternatively, the wireless communication control apparatus andthe wireless communication control method associated with the firstaspect of the invention may also have reception log storage means orstep for storing a reception log at command reception and targetidentifying means or step for identifying a target of command executionon the basis of the stored latest reception log.

[0035] In this case, the above-mentioned command processing means orstep may transmit commands only to the particular target specified bythe controller device of command transmission source.

[0036] Still alternatively, the above-mentioned command processing meansor step may transfer the received commands to all target devices whichsupport these commands in the above-mentioned communication cell.

[0037] In carrying out the invention and according to a second aspectthereof, there is provided a wireless communication control apparatus ora wireless communication control method for controlling, in a piconet ofa Bluetooth wireless network constituted by one master device and aplurality of slave devices, at least one slave device in the piconethaving a controller function for issuing commands and at least one slavedevice having a target function for supporting commands, the masterdevice having both controller and target functions, including:connecting means or step for establishing Bluetooth communication in thepiconet; controller/target function grasping means or step for graspinga slave device which functions as a target and/or a controller; andsupport command grasping means or step for managing the commandssupported by each target in the piconet.

[0038] In the piconet of the Bluetooth wireless network to which thewireless communication control apparatus and the wireless communicationcontrol method associated with the second aspect of the invention areapplied, each slave device is communicable only with the master device.On a predetermined profile, each of the master device and the slavedevices in the piconet may operate as the controller which issuescommands or a slave device which supports commands.

[0039] In addition, the wireless communication control apparatus and thewireless communication control method associated with the second aspectof the invention, when applied to a device which becomes the master inthe piconet of the Bluetooth wireless network preferably yield theeffects of the invention. Such a master device itself functions as bothcontroller and target on a predetermined control profile. Theabove-mentioned support command grasping means or step may also managethe commands supported by the master device itself.

[0040] According to the wireless communication control apparatus and thewireless communication control method associated with the second aspectof the invention, the master device may function as the systemcontroller to manage the control functions of the slave devicesoperating as targets in the piconet, or the commands supported by them.For a slave device operating as the controller in the piconet to controlanother slave device, the controller device may issue commands to themaster device which is a target. Then, the master device transfers, asthe controller device, the received commands to the target namely theslave device which supports these commands.

[0041] Consequently, if each slave device in the piconet functions asthe controller on the predetermined control profile, it may issuecommands to targets in the piconet without being aware of any otherdevices than the master device.

[0042] Likewise, each slave device functioning as a target on apredetermined control profile may only execute the commands receivedfrom the master device without being aware of any other devices than themaster device (namely without being aware of whether the receivedcommand is from another slave device which functions as the controller).

[0043] In other words, the slave device operating as the controllertransmits commands to the master device as a target and the other slavedevices operating as targets may only process the commands received fromthe master device. Namely, according to the wireless communicationcontrol apparatus and the wireless communication control methodassociated with the second aspect of the invention, control between theslave devices may be realized via the master device in the piconet ofthe Bluetooth wireless network in which each slave device iscommunicable only with the master device.

[0044] The above-mentioned controller/target function grasping means orstep lays a logical link (L2CAP) with each slave device in the piconetto inquire each slave device for its controller function or targetfunction by use of Service Discovery Protocol (SDP).

[0045] The above-mentioned support command grasping means or step lays alogical link (L2CAP) with each slave device operating as the target inthe piconet to inquire each slave device for support commands by amethod defined in an upper application protocol.

[0046] The wireless communication control apparatus or the wirelesscommunication control method associated with the second aspect of theinvention further including: command receiving means for receiving acommand, which is connected with the slave device operating as thecontroller in the piconet; and command processing means for processingthe received command.

[0047] This command processing means for step transfers receivedcommands to a targets which support these commands in the same piconet.

[0048] If the master device itself on which the wireless communicationcontrol apparatus or the wireless communication control methodassociated with the second aspect of the invention is implementedsupports commands, the above-mentioned command processing means or stepmay cause the master device itself to execute the commands.

[0049] If there are two or more target devices which support receivedcommands in the piconet, the controller device, which is the commandtransmission source, may have a function for specifying a particulartarget device as a device for command execution.

[0050] Alternatively, the wireless communication control apparatus orthe wireless communication control method associated with the secondaspect of the invention further including: reception log storage meansfor storing a reception log indicative of command reception; and targetidentifying means for identifying a target which executes the receivedcommand on the basis of the newest log stored in the reception logstorage means.

[0051] In this case, the above-mentioned command processing means orstep transfers received commands only to a particular command inaccordance with the specification by the controller device, which is thecommand transmission source.

[0052] Alternatively, the above-mentioned command processing means orstep transfers received commands to all target devices which supportthese commands in the above-mentioned communication cell.

[0053] In carrying out the invention and according to a third aspectthereof, there is provided a storage medium physically storing computersoftware in a computer-readable form, the computer software beingdescribed so as to execute, on a computer system, wireless communicationcontrol for controlling command exchange between devices in acommunication cell which is constituted by one master device and aplurality of slave devices, each slave device being capable ofcommunicating with only the master device, the computer softwareincluding the steps of: inquiring each device in the communication cellwhether each device operates as a controller or a target; inquiring eachdevice having a target function for a command supported thereby; andmanaging the commands supported by each target device.

[0054] In carrying out the invention and according to a fourth aspectthereof, there is provided a storage medium physically storing computersoftware in a computer-readable form, the computer software beingdescribed so as to execute, on a computer system, wireless communicationcontrol for controlling command exchange between devices in a piconet ofa Bluetooth wireless network constituted by one master device and aplurality of slave devices, at least one of the plurality of slavedevices in the piconet having a controller function for issuingcommands, at least one of the other slave devices having a targetfunction for supporting commands, and the master device being capable ofhaving both of the controller function and the target function, thecomputer software including the steps of: establishing Bluetoothcommunication in the piconet; grasping a slave device which functions asa target and/or a controller; and managing the commands supported byeach target in the piconet.

[0055] The storage media associated with the third and fourth aspects ofthe invention provide, in a computer-readable form, computer software togeneral-purpose computer systems which can execute a variety of programcodes, for example. These storage media are detachable and portablestorage media such as CD (Compact Disc), FD (Flexible Disk), and MO(Magneto-Optical disc) for example. Alternatively, it is technologicallypracticable to provide computer software to particular computer systemsvia transmission media such as networks (regardless of wired orwireless).

[0056] These storage media define the structural or functionalcooperative relationship between computer software and storage media inorder to realize predetermined computer software on computer systems. Inother words, installing predetermined computer software on computersystems through the storage media associated with the third and fourthaspects of the present invention realizes the cooperative action on thecomputer systems, thereby yielding the same operational effects as thoseof the wireless communication control apparatuses and the wirelesscommunication control methods associated with the first and secondaspects of the present invention.

[0057] In carrying out the invention and according to a fifth aspectthereof, there is provided a computer program being described in acomputer-readable form so as to execute, on a computer system, wirelesscommunication control for controlling command exchange between devicesin a communication cell which is constituted by one master device and aplurality of slave devices, each slave device being capable ofcommunicating with only the master device, the computer softwareincluding the steps of: inquiring each device in the communication cellwhether each device operates as a controller or a target; inquiring eachdevice having a target function for a command supported thereby; andmanaging the commands supported by each target device.

[0058] In carrying out the invention and according to a sixth aspectthereof, there is provided a computer program being described in acomputer-readable form so as to execute, on a computer system, wirelesscommunication control for controlling command exchange between devicesin a piconet of a Bluetooth wireless network constituted by one masterdevice and a plurality of slave devices, at least one of the pluralityof slave devices in the piconet having a controller function for issuingcommands, at least one of the other slave devices having a targetfunction for supporting commands, and the master device being capable ofhaving both of the controller function and the target function, thecomputer software including the steps of: establishing Bluetoothcommunication in the piconet; grasping a slave device which functions asa target and/or a controller; and managing the commands supported byeach target in the piconet.

[0059] The computer programs associated with the fifth and sixth aspectsof the invention define the computer programs described in acomputer-readable form so as to realize predetermined processing oncomputer systems. In other words, installing the computer programsassociated with the fifth and sixth aspects of the invention on computersystems brings out the cooperative action on computer systems, therebyyielding the same operational effects as those of the wirelesscommunication control apparatuses and the wireless communication controlmethods associated with the first and second aspects of the presentinvention.

[0060] This invention will be described in further detail by way ofexample with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0061]FIG. 1 is a schematic diagram illustrating a configuration of aBluetooth piconet practiced as one embodiment of the invention.

[0062]FIG. 2 is a functional block diagram illustrating a configurationof devices 11 through 13 which constitute a piconet 10 shown in FIG. 1.

[0063]FIG. 3 is a schematic diagram illustrating a structure of aprofile stack of AV Remote Control Profile (AVRCP).

[0064]FIG. 4 is a diagram illustrating a structure of an AVRCP commandframe by use of PASS THROUGH command for example.

[0065]FIG. 5 is a schematic diagram illustrating an example in which aplurality of slave devices of the same category exist within a piconet20 in a Bluetooth wireless network.

[0066]FIG. 6 is a flowchart approximately describing a processingprocedure of system control by a media player 21 which functions as asystem controller in the piconet shown in FIG. 5.

[0067]FIG. 7 is a flowchart approximately describing a processingprocedure for the media player 21 functioning as the system controllerprocesses a command transmitted from a remote commander 24 in aheadphone A control mode.

[0068]FIGS. 8 through 17 are flowcharts describing the processingprocedures of the system control by the media player 21 within thepiconet 20 shown in FIG. 5.

[0069]FIG. 18 is a schematic diagram illustrating a configuration inwhich one master device 31 and four slave devices 32, 33, 34, and 35exist within one piconet 30 in a Bluetooth wireless network.

[0070]FIG. 19 is a chart illustrating a processing procedure for a mediaplayer 31 which is the system controller to inquire slave devices 32through 34 functioning as AVRCP targets for their functions.

[0071]FIG. 20 is a chart illustrating a processing procedure for themedia player 31 which is the system controller to inquire each slavedevice functioning as an AVRCP target for a Specific Inquiry supportcommand.

[0072]FIG. 21 is a diagram schematically illustrating a structure of“Inquiry” message frame for the media player 31 which is the systemcontroller to inquire a headphone B34 functioning as an AVRCP targetwhether it supports command “volume up” or not.

[0073]FIG. 22 is a diagram schematically illustrating a structure of“Implemented” message frame for the headphone B34 which is an AVRCPtarget to return information that it supports command “volume up” to themedia player 31 which is the system controller.

[0074]FIG. 23 is a diagram schematically illustrating a structure of“Inquiry” message frame for the media player 31 which is the systemcontroller to inquire the headphone B34 which is an AVRCP target whetherit supports command “input select”.

[0075]FIG. 24 is a diagram schematically illustrating a structure of“Not Implemented” message frame for the headphone B34 which is an AVRCPtarget to return information that its does not support command “inputselect” to the medial player 31.

[0076]FIG. 25 is a chart illustrating a processing procedure in whichthe remote commander 35 functioning as the AVRCP controller transmitscommands to each AVRCP target via the media player 31 functioning as thesystem controller to perform remote control operations.

[0077]FIG. 26 is a chart illustrating a processing procedure in whichthe remote commander functioning as the AVRCP controller transmits aPASS THROUGH command to the medial player functioning as the systemcontroller to remotely control other slave devices, which are AVRCPtargets.

[0078]FIG. 27 is a diagram schematically illustrating a structure of“Control” message frame for the remote commander functioning as theAVRCP controller to transmit an F2 command to the media player 31functioning as the system controller.

[0079]FIG. 28 is a diagram schematically illustrating a structure of“Accepted” message frame for the media player 31 functioning as thesystem controller to return information that it has accepted the F1command to the remote commander 35 functioning as the AVRCP controller.

[0080]FIG. 29 is a diagram schematically illustrating a structure of“Control” message frame for the remote commander 35 functioning as theAVRCP controller to transmit a “Mute” command to the medial player 31functioning as the system controller.

[0081]FIG. 30 is a diagram schematically illustrating a structure of“Accepted” message frame for the media player 31 functioning as thesystem controller to return information that it has accepted the “Mute”command to the remote commander 35 functioning as the AVRCP controller.

[0082]FIG. 31 is a diagram schematically illustrating a structure of“Control” message frame for the media player 31 functioning as the AVRCPcontroller to transmit a “Mute” command to a TV tuner 32 which is anAVRCP target.

[0083]FIG. 32 is a diagram schematically illustrating a structure of“Accepted” message frame for the TV tuner 32 which is an AVRCP target toreturn information that it has accepted the “Mute” command to the mediaplayer 31 functioning as the AVRCP controller.

BEST MODE FOR CARRYING OUT THE INVENTION

[0084] This invention will be described in further detail by way ofexample with reference to the accompanying drawings.

[0085] First, a piconet 10 of a Bluetooth wireless network as shown inFIG. 1 is described below. As described earlier, the piconet 10 isconstituted by one master device given with the control function formaintaining the order of communication and up to seven slave devices.

[0086] If a plurality of slave devices exist in the same piconet 10, thecommunication between the master device and each of the slave devices isshared by all of these slave devices in a time division multiplexingmanner except in the case of broadcast communication. The unit in whichtime division multiplexing is executed is a time interval of 625microseconds called a “time slot.”

[0087] With respect to the directions of packet transfer between themaster and each slave in the same piconet 10, a packet is transferredfrom maser to slave if its slot number is even and from slave to masterif its slot number of odd. Thus, in Bluetooth, packets can betransferred between master and slave, but cannot be directly transferredbetween slave devices.

[0088] In the example shown in FIG. 1, Bluetooth is applied to thewireless connection between AV devices. The piconet 10 contains a mediaplayer 11 functioning as the master device and a headphone 12 and aremote commander 13, which are slave devices. The remote commander 13remotely controls the media player 11 for executing play control such asplay, stop, pause, fast forward and rewind and remotely controls theheadphone 12 for executing sound volume adjustment (volume up/down) forexample.

[0089]FIG. 2 schematically illustrates a configuration of the devices 11through 13 constituting the piconet 10 shown in FIG. 1.

[0090] The media player 11 is constituted by a Bluetooth interface block11A, a signal generating block 11B, a player control block 11C, and asystem control block 11D.

[0091] The Bluetooth interface block 11A is a functional block forrealizing the Bluetooth wireless connection in the piconet 10 andtransfers commands and responses with the slave devices 12 and 13 in thepiconet 10.

[0092] The signal generating block 11B is a functional block forgenerating signals for controlling such communication states in thepiconet 10 as the Bluetooth clock.

[0093] The player control block 11C is a functional block for realizingsuch media play control functions as play, stop, pause, fast forward andrewind of media loaded on the media player 11.

[0094] The system control block 11D is a functional block for realizingtotal control of the slave devices 12 and 13 in the piconet 10. In thepresent embodiment, the system control block 11D manages the controllerand target functions in the control profile AVRCP for remotelycontrolling AV equipment to enable control by one slave device ofanother slave device via the master device 11, to be more specific,control by the remote commander 13 of the headphone 12, another slavedevice. The details of the system control in the piconet 10 by thesystem control block 11D will be described later.

[0095] The headphone 12 is constituted by a Bluetooth interface block12A, a headphone control block 12B, and a signal processing block 12C.

[0096] The Bluetooth interface block 12A is a functional block forrealizing the Bluetooth wireless connection in the piconet 10 andtransfers commands, responses, and data streams with the master device11.

[0097] The headphone control block 12B is a functional block forrealizing such sound output functions as volume up, volume down, andmute.

[0098] The signal processing block 12C is a functional block forprocessing the control signals received from the master device 11 by theBluetooth wireless communication and the controls signals issued by theheadphone control block 12B.

[0099] In the present embodiment, the headphone 12 may be configured asa slave device compatible only to the conventional AV equipment profile“AV Remote Control Profile” (AVRCP).

[0100] The remote commander 13 is constituted by a Bluetooth interfaceblock 13A and a remote control block 13B.

[0101] The Bluetooth interface block 13A is a functional block forrealizing the Bluetooth wireless connection in the piconet 10 andtransfers commands and responses with the master device 11.

[0102] The remote control block 13B is a functional block for realizingmedia play control such as play, stop, pause, fast forward, and rewindof media loaded on the media player 11 and sound output control such asvolume up, volume down, and mute of the headphone 12.

[0103] In the present embodiment, as with the headphone 12, the remotecommander 13 may be configured as a slave device compatible only withthe conventional AV equipment control profile “AV Remote ControlProfile” (AVRCP).

[0104] The AV Remote Control Profile (AVRCP), one of the Bluetoothapplication profiles is intended to realize the AV equipment controlsimilar to infrared remote control on each Bluetooth wireless network.The command transmitting side is called a “controller,” while the sidewhich receives commands the returns responses is called a “target.”

[0105]FIG. 3 schematically illustrates the profile stack structure of AVRemote Control Profile (AVRCP).

[0106] In the figure, a baseband layer, an LMP layer, and an L2CAP layerare Bluetooth protocols equivalent to the first layer and the secondlayer of an OSI (Open Systems Interconnect) basic reference model.

[0107] An AVCTP (AV Control Transport Protocol) layer specifies theprocessing procedure and message exchange for controlling AV equipment.

[0108] An SDP layer specifies the Bluetooth service discovery protocoland allows the master device 11 functioning as the system controller todetect the controller function and target function of the slave devices12 and 13 in the piconet 10.

[0109] The AV control layer is an entity for controlling AV equipment onan AV/C command basis.

[0110] In the present embodiment, the headphone 12 has the AVRCP targetfunction so as to control volume up and volume down operations from theoutside.

[0111] The remote commander 13 has the AVRCP controller function so asto remotely control outside equipment including the headphone 12.

[0112] The media player 11 has both the AVRCP controller and targetfunctions. Namely, the media player 11 has the controller function fortransmitting the volume up and volume-down commands to the headphone 12and the target function for receiving the media play and stop commandsfor example from the remote commander 13 and processing them.

[0113] As described earlier, in the piconet 10, the media player 11 isdefined as the master device in the Bluetooth wireless communication andthe headphone 12 and the remote commander 13 are defined as its slavedevices.

[0114] The following describes an example of a so-called “universalremote commander” which may remotely control equipment of variouscategories.

[0115] Each of the remote commander of this type has keys includingplay, stop, FF, rewind, pause, volume up, volume down, channel up,channel down, up, down, right, left, and execute, thereby issuingcommands corresponding to user's key operations.

[0116] In the present embodiment, the remote commander 13 is defined asa slave device, so that it cannot communicate with the media player 11,which is the master device. In other words, the above-mentioned commandsissued from the remote commander 13 may be transmitted only to the mediaplayer 11.

[0117] On the other hand, the media player 11, which is the mate ofcommunication of the remote commander 13, can execute the commandsassociated with media play control such as play, stop, FF, rewind, andpause among the commands received from the remote commander 13, but,because no speaker is incorporated, cannot execute the commandsassociated with volume adjustment such as volume up and volume down.

[0118] Based on the function of the system control block 11D to bedescribed later, the media player 11 associated with the presentembodiment can become the system controller in the piconet 10 totransfer the received commands for volume up and volume down to theheadphone 12.

[0119] The following describes the processing procedure of the systemcontrol function in the piconet 10 of the media player 11 to be realizedby the system control block 11D.

[0120] (1) Establishing the Bluetooth communication in the piconet:

[0121] The connection of the Bluetooth communication in the piconet 10is established by going through inquiry and page phases. Consequently,the media player 11 operating as the system controller in the piconet 10is defined as the master device.

[0122] It should be noted that the inquiry denotes herein thefirst-stage processing phase for providing the synchronization inpiconet, in which the master device 11 checks the existence of the slavedevices 12 and 13 in the piconet 10. The page denotes herein thesecond-stage processing phase for providing the synchronization inpiconet, in which, on the basis of a result of the inquiry, the masterdevice establishes the synchronization in piconet between the particularslave devices 12 and 13.

[0123] (2) Grasping the AVRCP controller/target functions for each slavedevice in piconet:

[0124] The media player 11 as the system controller lays the connectionof a logical link (L2CAP) for performing service discovery on theheadphone 12 and the remote commander 13 which are the slave devices inthe same piconet 10 and, by use of the service discovery protocol (SDP),grasps the functions in the AVRCP protocol of the headphone 12 and theremote commander 13.

[0125] In the example shown in FIG. 1, by use of SDP, the media player11 as the system controller knows that the remote commander 13 has anAVRCP controller function and the headphone 12 is compatible with anAVRCP target function. In the present embodiment, the headphone 12 iscompatible with an AVRCP category 2 (monitor/amplifier) function, whichis also grasped by the SDP procedure. (These items of information areheld in each device as a service record.)

[0126] Next, the media player 11 as the system controller lays theconnection of the logical link (L2CAP) for device control with theheadphone 12. Then, the media player 11 transmits a support inquirycommand to check which of AVRCP commands is supported by the headphone.In AVRCP, an AV/C command is used as the protocol for AV equipmentcontrol (refer to FIG. 3).

[0127] For a command for remote commander control, a PASS THROUGHcommand defined in the AV/C panel subunit is applied. FIG. 4 shows thestructure of AVRCP command frame by use of the PASS THROUGH command forexample. As shown, this command frame is configured by a packet header,an L2CAP header, an AV control transport protocol (AVCTP) and an AV/Ccommand in this order. The packet header includes an identifier foridentifying a slave in communication in the piconet. The AV/C commandsinclude a SPECIFIC INQUIRY command for inquiring the support conditionfor each control command. When the SPECIFIC INQUIRY command istransmitted attached with the same operation code as control and anoperand, the implementation on the target device may be known withoutinvolving an actual operation. By this SPECIFIC INQUIRY command, theimplementation condition of each operation of the PASS THROUGH commandmay be known.

[0128] In the present embodiment, the belonging of the headphone tocategory 2 (described above) is known in advance, so that only theoperation of category 2 may be checked. The following table (Table 1)lists the operations in category 2. TABLE 1 0 1 . . . 9 dot enter soundselect input select display information help power volume up volume downmute vendor unique

[0129] In category 2, the support in target device of volume up andvolume down is mandatory, so that, whether they are supported or notneed to be checked. For example, assumed that the headphone 12 alsosupport mute in addition to volume up and volume down. Then, theheadphone 12 which received the SPECIFIC INQUIRY command for eachoperation ID from the media player 11 returns response calledIMPLEMENTED to the command which corresponds to these three implementedoperations. For the inquiries for the other operations not implemented,the headphone 12 returns a response called NOT IMPLEMENTED.

[0130] (3) Managing support commands for each AVRCP target in piconet:

[0131] The media player 11 as the system controller also generates alist of commands to be supported when the media player 11 itselffunctions as a target device and a list of commands for controlling thetarget device (the headphone 12 in the example shown in FIG. 1) in thepiconet 10 by the media player 11 (namely, the commands supported by theheadphone 12). An example of generated lists is shown in Table 2 below.TABLE 2 Commands (operations) supported by medial Commands (operations)player supported by headphone play volume up stop volume down pause muterecord rewind fast forward

[0132] (4) Connecting AVRCP controller with Bluetooth master device:

[0133] The remote commander 13 lays, as the AVRCP controller, theconnection of a logical link (L2CAP) with the media player 11 in thepiconet 10. In response, the media player 11 responds to this connectionwhen it becomes ready for functioning as the system controller.

[0134] (5) Transmitting commands form AVRCP controller:

[0135] In order to transmit commands to AV equipment, the user operatescorresponding keys on the remote commander 13. In response, the remotecommander 13 transmits, as the AVRCP controller, specified commands tothe media player 11 which is the AVRCP target.

[0136] (6) Transferring commands to AVRCP target:

[0137] The media player 11 which is the AVRCP target incorporates thesystem control block 11D (described above). This system control block11D interprets the commands received from the AVRCP controller (theremote commander 13 shown in FIG. 1) in the piconet 10.

[0138] If the command interpretation indicates that the received commandis one of the commands listed in the left column of Table 2 such as“play” indicative of media play start, namely the received command isfor the media play control supported by the media player 11 itself, thenthe media player 11 passes this command to the player control block 11Cin it and returns an ACCEPTED response indicative of the acceptance ofthe command to the requesting remote commander 13.

[0139] If the command interpretation indicates that the received commandis one of the commands listed in the right column of Table 2 such as“volume up,” namely the received command is supported by the AVRCPtarget (the headphone 12 shown in FIG. 1) other than the media player11, the media player 11 returns an ACCEPTED response indicative of theacceptance of the command to the command transmitting remote commander13 and transfers the received command directly to the supporting device,namely the headphone 12.

[0140] If the command received by the system control block is not listedin Table 2, namely, not supported by any AVRCP targets in the piconet10, then the media player 11 returns NOT IMPLEMENTED response to thecommand transmitting remote commander 13, thereby ignoring theprocessing of the received command.

[0141] (7) Executing commands by AVRCP target:

[0142] As described, when command transmission to the headphone 12 hasbeen performed, the headphone 12 interprets that the media player 11 asthe Bluetooth master device has transmitted the volume up command bybecoming the controller (in other words, without being aware that thecommand has been issued from the remote commander 13) and returns anACCEPTED response indicative of the acceptance of the command to themedia player 11, thereby executing the volume up command.

[0143] As described, on the AVRCP control profile, the media player 11has the target function and the controller function on its own andgenerates a command list in the system control block 11D to grasp thecommands supported by each of the target devices (the headphone 12 andthe media player 11 itself in the example shown in FIG. 1) in thepiconet 10.

[0144] As a result, the remote commander 13 may only control the mediaplayer 11 as the target having the function of the headphone 12 bybecoming the AVRCP controller. Therefore, the remote commander 13 may beconfigured as a slave device compatible with the conventional AVRCP.

[0145] The headphone 12 may only receive and execute, as the AVRCPtarget, the command from the media player 11 which is the AVRCPcontroller. Therefore, the headphone 12 may be configured as a slavedevice compatible with the conventional AVRCP. Obviously, the headphone12 need not be aware that the received command is from the remotecommander 13.

[0146] The following describes an exemplary application which uses thesystem controller function of a Bluetooth master device such asmentioned above.

[0147] For example, assume that the media player 11 as the master devicehave an LCD (Liquid Crystal Display) display function (not shown) and avariety of settings associated with AVRCP command control can beperformed on this LCD (Liquid Crystal Display) display function.

[0148] In this case, it may also be specified on a menu screen (notshown) whether to restrict the operation on the remote commander 13 tothe main frame of the media player 11 or extend it to the other slavedevices in the piconet 10, namely the targets. Alternatively, instead ofusing a display device such as LCD, an on/off switch associated withcommand transfer or an equivalent mechanical button (not shown) may bearranged on the main frame of the media player 11.

[0149] In more sophisticated applications, the above-mentionedconfiguration is also applicable to the case in which there are devicesof the same category (namely, the target devices which support the samecommand) in one piconet 10.

[0150]FIG. 5 shows an example in which two or more slave devices of thesame category in one piconet 20 a Bluetooth wireless network.

[0151] In the piconet 20 shown, there are a media player 21 as themaster device, a headphone A22 and a headphone B23 as slave devices, anda remote commander 24 as a slave device.

[0152] The remote commander 24 which is a slave device in the piconet 20operates, on the control profile AVRCP, as the controller which issuescommands associated with media play control and output volumeadjustment.

[0153] The media player 21 which is the master device in the piconet 20has, on the control profile AVRCP, the controller function for issuingcommands such as volume control commands to the headphone A22 and theheadphone B23 and the target function for performing media play controlsuch as play, stop, pause, fast forward, and rewind of media in responseto the commands from the remote commander 24.

[0154] Each of the headphone A22 and the headphone B23 which are theslave devices in the piconet 20 supports, on the control profile AVRCP,as a target, the commands of the same category associated with volumeadjustment.

[0155] As shown in FIG. 5, if the headphone A22 and the headphone B23exist in the piconet 20 in which the media player 21 is the master, themedia player 21 as the system controller in the piconet 20 is not sureto which of these headphones a command “volume up” from the remotecommander 24 is to be transferred.

[0156] Hence, in the present embodiment, if there are two or moretargets of the same category in a piconet, the system control rules aredetermined so that the controller, from which commands are issued,namely, the remote commander 24 can specify to which of these target thecommands are to be transferred.

[0157] For example, if functions keys such as F1, F2, F3, F4, and so onare arranged on the remote commander 24, the key button operations areassigned to the specification of the target devices. The following showsan example of the assignment of the function keys to the specificationof target devices.

[0158] To transmit commands to the headphone A (to adjust the volume ofthe headphone A), press F1 key and then press a command button (forexample, volume up).

[0159] To transmit commands to the headphone B (to adjust the volume ofthe headphone B), press F2 key and then press a command button (forexample, volume up).

[0160] To transmit commands to both the headphone A and the headphone B(to adjust the volumes of both the headphones A and B), press F3 key andthen press a command button (for example, volume up).

[0161] To end the transmission of commands to the headphone A and theheadphone B (to end the operations of the headphone A and the headphoneB), press F4 key and then press a command button (for example, volumeup).

[0162]FIG. 6 approximately shows a flowchart describing a system controlprocessing procedure by the media player 21 as the system controller inthe piconet 20 shown in FIG. 5. It is assumed, however, that the mediaplayer 21 grasp the controller and/or target function on the controlprofile AVRCP of the slave devices 22, 23, and 24 in the piconet 20through the procedure described above and manage the commands supportedby the target devices 22 and 23. The following describes the systemcontrol processing in he piconet 20 with reference to the flowchartshown in FIG. 6.

[0163] Receiving a command from the remote commander 24 (step S1), themedia player 21 first determines whether the headphone A control mode ison (step S2). When function key F1 is pressed, the remote commander 24can specify that it is the control mode of the headphone A22 (asdescribed above).

[0164] If the headphone A control mode is found on, the procedure goesto decision block S5 to further determine whether a command associatedwith F2, F3, or F4 has been received from the remote commander 24.

[0165] If a command associated with F2, F3, or F4 has not been receivedfrom the remote commander 24, the media player 21 controls the headphoneA22 in the headphone A control mode in accordance with the commandreceived from the remote commander 24.

[0166] On the other hand, if a command associated with F2, F3, or F4 hasbeen received from the remote commander 24, the headphone B control modeis entered in response to the reception of F2 command. And, in responseto the reception of F3 command, the headphone AB control mode isentered. In response to the reception of F4 command, the operations ofthe headphone A and the headphone B are stopped, upon which the controlmode of the media player 21 is entered.

[0167] If, in decision block S2, the headphone A mode is found notentered, then the procedure goes to subsequent decision block S3 todetermine whether the headphone AB control mode has been entered. Whenfunction key F3 is pressed, the remote commander 24 can specify that itis the headphone AB control mode (as described above).

[0168] If the headphone AB mode is found entered, the procedure goes todecision block S8 to check if a command associated with F1, F2, or F4has been received from the remote commander 24.

[0169] If a command associated with F1, F2, or F4 has not been receivedfrom the remote commander 24, the media player 21 controls both theheadphones A and B in the headphone AB control mode in accordance withthe command received from the remote commander 24.

[0170] On the other hand, if a command associated with F1, F2, or F4 hasbeen received from the remote commander 24, then the headphone A controlmode is entered in response to the reception of F1 command. And, inresponse to the reception of F2 command, the headphone B control mode isentered. In response to the reception of F4 command, the operations ofthe headphones A and B are stopped, upon which the control mode of themain frame of the media player 21 is entered.

[0171] If the headphone AB control mode is found not entered in decisionblock S3, then the procedure goes to subsequent decision block S4 todetermine whether the headphone B mode is entered. When function key F2is pressed, the remote commander 24 can specify that it is the headphoneB control mode (as described above).

[0172] If the headphone B control mode is found entered, then theprocedure goes to decision block S6 to further check if a commandassociated with F1, F3, or F4 has been received from the remotecommander 24.

[0173] If a command associated with F1, F3, or F4 has not been receivedfrom the remote commander 24, then the media player 21 controls theheadphone B in the headphone B control mode in accordance with thecommand received from the remote commander 24.

[0174] On the other hand, if a command associated with F1, F3, or F4 hasbeen received from the remote commander 24, the headphone A control modeis entered in response to the reception of F1 command. And, in responseto the reception of F3 command, the control mode of both the headphonesA and B is entered. In response to the reception of F4 command, theoperations of the headphones A and B are stopped, upon which the controlmode of the main frame of the media player 21 is entered.

[0175] If the headphone B control mode is found not entered in decisionblock S4, then the procedure goes to subsequent decision block S7 tocheck if a command associated with F1, F2, or F4 has been received fromthe remote commander 24.

[0176] If a command associated with F1, F2, or F3 has not been receivedfrom the remote commander 24, the media player 21 executes the commandreceived from the remote commander 24 in the control mode of the mainframe of the media player 21.

[0177] On the other hand, if a command associated with F1, F2, or F3 hasbeen received from the remote commander 24, then the headphone A controlmode is entered in response to the reception of F1 command. And, inresponse to the reception of F2 command, the headphone B control mode isentered. In response to the reception of F3 command, the headphone ABcontrol mode is entered.

[0178]FIG. 7 approximately shows a flowchart describing a procedure forthe media player 21 as the system controller to process the commandsfrom the remote commander 24 in the headphone A control mode. Thefollowing describes the command processing by the media player 21 withreference to this flowchart.

[0179] Receiving a command from the remote commander 24 the systemcontrol block (described above) of the media player 21 determineswhether the received command is listed in the command list (Table 2) ofthe headphone A22, in other words, whether the received command issupported by the headphone A22 which is a target (step S11).

[0180] If the received command is found supported by the headphone A,then an ACCEPTED response indicative of the acceptance of the command isreturned to the command transmitting remote commander 24 (step S12). Onthe other hand, if the received command is fount not supported by theheadphone A, then a NOT IMPLEMENTED response is returned to the commandtransmitting remote commander 24 (step S13), upon which this processingroutine comes to an end in its entirety.

[0181] Next, the command is transferred to the headphone A (step S14),upon which this processing routine comes to an end in its entirety.

[0182] The following details a system control processing procedure bythe media player 21 which is the system controller in the piconet 20shown in FIG. 5 with reference to FIGS. 8 through 17. It is assumed herethat the media player 21 grasp the controller and target functions onthe control profile AVRCP of the slave devices 22, 23, and 24 in thepiconet 10 through the above-mentioned procedure and manage the supportcommands of the target devices 22 and 23.

[0183] Referring to FIG. 8, receiving a command from the remotecommander 24 (step S101), the media player 21 first determines whetherthe received command is “F1” or not (step S102). If the received commandis found not “F1,” the media player 21 determines whether the receivedcommand is “F2,” “F3,” or “F4” (steps S102, S103, and S104). Because the“F1,” “F2,” “F3,” and “F4” commands are used to specify device controlmodes, if the received command is one of “F1,” “F2,” “F3,” and “F4,” theprocedure goes to the command processing shown in FIGS. 9, 10, 11, or 12accordingly. If the received command is one of “F1,” “F2,” “F3,” and“F4,” then the received command is not for specifying the device controlmode but for control itself, so that the procedure goes to the devicecontrol command processing shown in FIG. 13.

[0184]FIG. 9 shows a flowchart of a processing procedure to be executedby the media player 21 when “F1” command is received. First, the mediaplayer 21 determines the current control mode (step S106). Then, themedia player 21 determines whether the headphone A control mode hasalready been entered (step S107). If this mode has not been entered, the“headphone A control mode” is entered (step S108). If the headphone Acontrol mode has been entered, the mode change does not take place.Next, an ACCEPTED response indicative of the acceptance of the commandis returned to the command transmitting remote commander 24 (step S109),upon which this processing routines comes to an end in its entirety.

[0185]FIG. 10 shows a flowchart describing a processing procedure to beexecuted by the media player 21 when it receives “F2” command. First,the media player 21 determines the current control mode (step S110).Then, the media player 21 determines whether the headphone B controlmode has already been entered (step S111). If this mode has not beenentered, the “headphone B control mode” is entered (step S112). If theheadphone B control mode has been entered, the mode change does not takeplace. Next, an ACCEPTED response indicative the acceptance of thecommand is returned to the command transmitting remote commander 24(step S113), upon which this processing routines comes to an end in itsentirety.

[0186]FIG. 11 shows a flowchart describing a processing procedure to beexecuted by the media player 21 when it receives “F3” command. First,the media player 21 determines the current control mode (step S114).Then, the media player 21 determines whether the headphone AB controlmode has already been entered (step S115). If this mode has not beenentered, the “headphone AB control mode” is entered (step S116). If theheadphone AB control mode has been entered, the mode change does nottake place. Next, an ACCEPTED response indicative the acceptance of thecommand is returned to the command transmitting remote commander 24(step S117), upon which this processing routines comes to an end in itsentirety.

[0187]FIG. 12 shows a flowchart describing a processing procedure to beexecuted by the media player 21 when it receives “F4” command. First,the media player 21 determines the current control mode (step S118).Then, the media player 21 determines whether the main frame control modehas already been entered (step S119). If this mode has not been entered,the “main frame control mode” is entered (step S120). If the main framecontrol mode has been entered, the mode change does not take place.Next, an ACCEPTED response indicative the acceptance of the command isreturned to the command transmitting remote commander 24 (step S121),upon which this processing routines comes to an end in its entirety.

[0188]FIG. 13 shows a flowchart describing a device control commandprocessing procedure to be executed by the media player 21. First, themedia player 21 checks the current control mode (step S122) whether itis the headphone A control mode (step S123), the headphone B controlmode (step S124), or the headphone AB control mode (step S125). If thecurrent mode is any one of these modes, then the procedure goes to thecontrol mode processing shown in FIG. 14, FIG. 15, or FIG. 16accordingly. If the current mode is none of these control modes, then itis the mode for controlling the main frame of the media player 21 andthe procedure goes to the processing shown in FIG. 17.

[0189]FIG. 14 shows a flowchart describing a procedure for the mediaplayer 21 that is the system controller to process the commandstransmitted from the remote commander 24 that is the controller in theheadphone A control mode.

[0190] The system control block in the media player 21 checks thecommand received from the remote commander 24 (step S126) to see whetherit is listed in the command list (refer to Table 2) of the headphoneA22, in other words, whether the received command is supported by theheadphone A22 that is a target (step S127).

[0191] If the received command is found supported by the headphone A22,then an ACCEPTED response indicative of the acceptance of the command isreturned to the command transmitting remote commander 24 (step S128)Then, the command is transferred to the headphone A22 (step S129), uponwhich this processing routine comes to an end in its entirety. On theother hand, if the received command is found not supported by theheadphone A22, then a NOT IMPLEMENTED response is returned to thecommand transmitting remote commander 24 (step S130), upon which thisprocessing routine comes to an end in its entirety.

[0192]FIG. 15 shows a flowchart describing a procedure for the mediaplayer 21 that is the system controller to process the commandstransmitted from the remote commander 24 that is the controller in theheadphone B control mode.

[0193] The system control block in the media player 21 checks thecommand received from the remote commander 24 (step S131) to see whetherit is listed in the command list of the headphone B23, in other words,whether the received command is supported by the headphone B23 that is atarget (step S132).

[0194] If the received command is found supported by the headphone B23,then an ACCEPTED response indicative of the acceptance of the command isreturned to the command transmitting remote commander 24 (step S133).Then, the command is transferred to the headphone B23 (step S133), uponwhich this processing routine comes to an end in its entirety. On theother hand, if the received command is found not supported by theheadphone B23, then a NOT IMPLEMENTED response is returned to thecommand transmitting remote commander 24 (step S135), upon which thisprocessing routine comes to an end in its entirety.

[0195]FIG. 16 shows a flowchart describing a procedure for the mediaplayer 21 that is the system controller to process the commandstransmitted from the remote commander 24 that is the controller in theheadphone AB control mode.

[0196] The system control block in the media player 21 checks thecommand received from the remote commander 24 (step S136) to see whetherit is listed in the command list of the headphone A 22 or B23 (refer toTable 2), in other words, whether the received command is supported bythe headphone A22 that is a target (step S137).

[0197] If the received command is found supported by the headphone A22or B23, then an ACCEPTED response indicative of the acceptance of thecommand is returned to the command transmitting remote commander 24(step S138). Then, the command is transferred to the headphones A22 andB23 (steps S139 and S140), upon which this processing routine comes toan end in its entirety. On the other hand, if the received command isfound not supported by the headphone A22 or B23, then a NOT IMPLEMENTEDresponse is returned to the command transmitting remote commander 24(step S141), upon which this processing routine comes to an end in itsentirety.

[0198]FIG. 17 shows a flowchart describing a procedure for the mediaplayer 21 that is the system controller to process the commands receivedfrom the remote commander 24 that is the controller in the main framecontrol mode.

[0199] The system control block in the media player 21 checks a commandreceived from the remote commander 24 (step S142) whether it is listedin the list of commands (Table 2) supported by the main frame of themedia player 21 (step S143).

[0200] If the received command is found supported by the media player 21itself, the command is passed to the player control block in the mediaplayer 21 of the same model (step S144). At this moment, it is checkedwhether the command can be executed or not due to emergency such as afailure of the player control block (step S145).

[0201] If the command is found executable, then an ACCEPTED response isreturned to the command transmitting remote commander 24 (step S146),upon which this processing routine comes to an end in its entirety. Ifthe received command is supported but cannot currently be executed, aREJECTED response indicative of the rejection of the command is returned(step S146), upon which this processing routine comes to an end in itsentirety. If the received command is found not one supported by themedia player 21 itself, a NOT IMPLEMENTED response indicative thereof isreturned (step S148), upon which this processing routine comes to an endin its entirety.

[0202] The following describes one embodiment of the present inventionby use of an example in which the Bluetooth master device that is thesystem controller processes the transfer of commands between AVRCPcontroller and AVRCP target in a Bluetooth piconet.

[0203]FIG. 18 illustrates there are one master device 31 and four slavedevices 32, 33, 34, and 35 in one piconet 30 of a Bluetooth wirelessnetwork.

[0204] As described earlier, the master device 31 is provided with acontrol function to maintain the order of communication. If a pluralityof slaves exist in a same piconet 10, the communication between slavesand master is shared in a time division multiplexing manner between allthe slave devices except in the case of broadcast communication. Theunit of time division multiplexing is a time interval of 625microseconds called “time slot.”

[0205] With respect to the directions of packet transfer between themaster and each slave in the same piconet 10, a packet is transferredfrom maser to slave if its slot number is even and from slave to masterif its slot number of odd. Thus, in Bluetooth, packets can betransferred between master and slave, but cannot be directly transferredbetween slave devices.

[0206] In the example shown in FIG. 18, the piconet 30 includes a mediaplayer 31 as the master device, a television (TV) tuner 32 as a slavedevice, headphones 33 and 34 as slave devices, and a remote commander 35as a slave device. The remote commander 35 remotely controls the mediaplayer 31 in play control such as media play, stop, pause, fast forward,and rewind and the TV tuner 32 in tuning, and the headphones 33 and 34in volume adjustment.

[0207] In the piconet 30, one of the Bluetooth application files, AVRemote Control Profile (AVRCP), is implemented. On the AVRCP profile,the remote commander 35 as a slave device has a function of thecontroller for transmitting commands to other devices, namely targets,in the piconet 30. The media player 31 as the master device has both thefunctions of the controller for command transmission and the target forcommand support. The TV tuner 32 and the headphones A33 and B34 asslaves each have an AVRCP target which supports the commands issued bythe AVRCP controller.

[0208] The media player 31 as the master device of the piconet 30 mayoperate as the system controller to inquire each slave device in thepiconet 30 whether it has the control function and the target functionon the control profile AVRCP.

[0209] In addition, the media player 31 as the system controller mayinquire the slave devices 32, 33, and 34 functioning as AVRCP targets inthe piconet 30 to detect the commands supported by these slave devices.The media player 31 generates a command list in the piconet 30. Anexample of this command list is shown in Table 3 below. TABLE 3 CommandsCommands Commands Commands supported by supported by supported bysupported by media player TV tuner headphone A headphone B Play Channelup Volume up Volume up Stop Channel down Volume down Volume down PauseVolume up Mute Record Volume down Rewind Mute Fast forward

[0210] The following describes a processing procedure in which the mediaplayer 31 as the system controller inquires the slave devices 32 through34 functioning as targets on the control profile AVRCP for theirfunctions in the piconet 30 with reference to FIG. 19.

[0211] First, the media player 31 which is the master device and thesystem controller lays the L2CAP channel for Service Discovery Protocol(SDP) with the TV tuner 32 and, on the basis of the Service Discoveryprocedure, detects that the TV tuner 32 is a target device on thecontrol profile AVRCP and the compatible with the tuner function andamplifier function. Then, the media player 31 clears the L2CAP channelwith the TV tuner 32.

[0212] Next, the media player 31 lays the L2CAP channel for ServiceDiscovery Protocol (SDP) with the headphone A33 which is another slavedevice in the piconet 30 and, on the basis of the Service Discoveryprocedure, detects that the headphone A33 is a target device on thecontrol profile AVRCP and compatible with the headphone function. Then,the media player 31 clears the L2CAP channel with the headphone A33.

[0213] Then, the media player 31 lays the L2CAP channel for ServiceDiscovery Protocol (SDP) with the headphone B34 which is another slavedevice in the piconet 30 and, on the basis of the Service Discoveryprocedure, detects that the headphone B34 is a target device on thecontrol profile AVRCP and compatible with the headphone function. Then,the media player 31 clears the L2CAP channel with the headphone B34.

[0214] Further, the media player 31 as the system controller lays theL2CAP channel for control with the TV tuner 32 as a slave device toinquire, by use of Specific Inquiry, the TV tuner 32 for the commandssupported thereby and detect these commands.

[0215] Next, the media player 31 lays the L2CAP channel for control withthe headphone A33 as a slave device and inquires, by use of SpecificInquiry, the headphone A33 for the commands supported as an AVRCP targetthereby and detects them.

[0216] Then, the media player 31 lays the L2CAP channel for control withthe headphone B34 as a slave device and, by use of Specific Inquiry,inquires the headphone B34 for the commands supported as an AVRCP targetthereby and detect them.

[0217] Thus, the media player 31 as the system controller may detect thecommands supported by the AVRCP target devices in the piconet 30 by useof the ordinary Bluetooth communication and, as a result, generate thecommand list shown in Table 3 mentioned above.

[0218] The following details the processing in which the media player 31as the system controller inquires each AVRCP target for the commandssupported thereby by use of Specific Inquiry. In what follows, it isassumed that the inquiry is directed to the headphone B34 as an AVRCPtarget.

[0219] The media player 31 as the system controller transmits a SpecificInquiry message to the headphone B34 as an AVRCP target to inquirewhether the headphone B34 supports command “volume up” or not.

[0220] For this Specific Inquiry message frame, a PASS THROUGH commandmay be applied, the frame structure thereof being schematicallyillustrated in FIG. 21. As shown in the figure, “Specific Inquiry” isspecified in Ctype/response field of the message frame. PASS THROUGH iswritten to the operation code and an operation identifier (here, command“volume up”) is written to the operand.

[0221] In response, the headphone B34 as an AVRCP target returnsImplemented message because it supports the inquired command “volumeup.”

[0222] For this Implemented message frame, a PASS THROUGH command may beapplied, the frame structure thereof being schematically illustrated inFIG. 22. As shown in the figure, “Implemented” is specified inCtype/response field of the message frame. PASS THROUGH is written tothe operation code and an operation identifier (here, command “volumeup”) is written to the operand.

[0223] The media player 31 as the system controller transmits Inquirymessage to the headphone B34 as an AVRCP target to inquire whethercommand “input select” is supported thereby.

[0224] For this Specific Inquiry message frame, a PASS THROUGH commandmay be applied, the frame structure thereof being schematically shown inFIG. 23. “Specific Inquiry” is specified in Ctype/response field of themessage frame. PASS THROUGH is written to the operation code and anoperation identifier (here, command “input select”) is written to theoperand.

[0225] In response, the headphone B34 as an AVRCP target returns NotImplemented message because it does not support the inquired command“input select.”

[0226] For this Not Implemented message frame, a PASS THROUGH commandmay be applied, the frame structure thereof being schematically shown inFIG. 24. As shown in the figure, “Not Implemented” is specified inCtype/response field of the message frame. PASS THROUGH is written tothe operation code and an operation identifier (here, command “inputselect”) is written to the operand.

[0227] The following describes, with reference to FIG. 25, a processingprocedure in which the remote commander 35 functioning as the AVRCPcontroller transmits a PASS THROUGH command to each AVRCP target via themedia player 31 as the system controller for remote control operation.

[0228] It should be noted that the media player 31 f as the systemcontroller is also the master device in the piconet 30. In the exampleshown below, the remote commander 35 may be set to the TV tuner controlmode by F1 command, the headphone A control mode by F2 command, and theheadphone B control mode by F3 command.

[0229] The remote commander 35 which is the AVRCP controller is a slavedevice in the piconet 30 and can communicate only with the media player31 which is the master device and the system controller. Therefore, totransmit commands to other slave devices 32 through 34 which are AVRCPtargets, the remote commander 35 first lays the L2CAP channel forcontrol with the media player 31 which is the master device.

[0230] Then, upon establishment of the L2CAP channel for control withthe media player 31, the remote commander 35 transmits F1 command to themedia player 31 which is the system controller.

[0231] In response, the media player 31 interprets the received F1command to set the control mode of the TV tuner 32.

[0232] Further, the remote commander 35 as the AVRCP controllertransmits a mute command to the media player 31 which is an AVRCPtarget.

[0233] In response, the media player 31 references the command list suchas Table 3 to detect that the received mute command is supported by boththe TV tuner 32 and the headphone A33. In this case, the TV tunercontrol mode is already set by F1 command issued last. Therefore, themedia player 31 as the AVRCP controller transfers the mute command onlyto the TV tuner 32 which is an AVRCP target.

[0234] Next, the remote commander 35 as the AVRCP controller transmits achannel up command to the media player 31 which is an AVRCP target.

[0235] In response, the media player 31 references the command list asshown in Table 3 mentioned above to detect that the channel up commandis supported only by the TV tuner 32. Then, the media player 31 as theAVRCP controller transfers the channel up command to the TV tuner 32which is an AVRCP target.

[0236] Next, the remote commander 35 as the AVRCP controller transmits aplay command to the media player 31 which is an AVRCP target.

[0237] In response, the media player 31 references the command list asshown in Table 3 mentioned above to detect that the play command issupported only by the media player 31 itself. Therefore, the mediaplayer 31 as an AVRCP target executes the play command on its own.

[0238] Then, the remote commander 35 transmits F3 command to the mediaplayer 31 which is the system controller.

[0239] In response, the media player 31 interprets the received F3command to set the control mode of the headphone B34.

[0240] Further, the remote commander 35 as the AVRCP controllertransmits a volume up command to the media player 31 which is an AVRCPtarget.

[0241] In response, the media player 31 references the command list asshown in Table 3 mentioned above to detect that the volume up command issupported by the TV tuner 32 and the headphones A33 and B34. In thiscase, the headphone B control mode is already set by the F3 commandissued last. Therefore, the media player 31 as the AVRCP controllertransfers the volume up command only to the headphone B34 which is anAVRCP target.

[0242] The following details, with reference to FIG. 26, a processingprocedure in which the remote commander 35 functioning as the AVRCPcontroller transmits a PASS THROUGH command to the media player 31 whichis the system controller to remotely control other slave devices whichare AVRCP targets. In what follows, it is assumed that the remotecommander 35 remotely control the TV tuner 32 which is an AVRCP target.

[0243] The remote commander 35 which is the AVRCP controller is a slavedevice in the piconet 30 and therefore can communicate only with themedia player 31 which is the master device. Therefore, to set the TVtuner control mode, the remote commander 35 transmits F1 command to themedia player 31.

[0244] For this F1 command transmission, a PASS THROUGH command may beapplied, the frame structure thereof being schematically shown in FIG.27. As shown in the figure, “Control” is specified in Ctype/responsefield of the message frame. PASS THROUGH is written to the operationcode and an operation identifier (here, command “F1”) is written to theoperand.

[0245] In response, the media player 31 as the system controller acceptsthe F1 command and sets the TV tuner control mode, returning an Acceptedmessage indicative of the acceptance of the F1 command to the remotecommander 35 which is the AVRCP controller.

[0246] For the transmission of the Accepted message, a PASS THROUGHcommand may be applied, the frame structure thereof being schematicallyshown in FIG. 28. As shown in the figure, “Accepted” is specified inCtype/response field of the message frame. PASS THROUGH is written tothe operation code and an operation identifier (here, command “F1”) iswritten to the operand.

[0247] Also, the remote controller 35 as a slave device and the AVRCPcontroller transmits a mute command to the media player 31 which is themaster device and an AVRCP target.

[0248] For the transmission of this mute command, a PASS THROUGH commandmay be applied, the frame structure thereof being schematically shown inFIG. 29. As shown in the figure, “Control” is specified inCtype/response field of the message frame. PASS THROUGH is written tothe operation code and an operation identifier (here, command “mute”) iswritten to the operand.

[0249] In response, the media player 31 as the system controller acceptsthe mute command and references the command list as shown in Table 3mentioned above to detect that the received mute command is supported bythe AVRCP target in the piconet 30, returning an Accepted messageindicative of the acceptance of the mute command to the remote commander35 which is the AVRCP controller.

[0250] For the transmission of this Accepted message, a PASS THROUGHcommand may be applied, the frame structure thereof being schematicallyshown on FIG. 30. As shown in the figure, “Accepted” is specified inCtype/response field of the message frame. PASS THROUGH is written tothe operation code and an operation identifier (here, command “mute”) iswritten to the operand.

[0251] In the piconet 30, the TV tuner 32 and the headphone A33 whichare AVRCP targets support the mute command. In this case, the TV tunercontrol mode is already set by the F1 command issued last. Therefore,the media player 31 as the system controller transfers, as the AVRCPcontroller, the mute command to the TV tuner 32 which is an AVRCPtarget.

[0252] For the transmission of this mute command, a PASS THROUGH commandmay be applied, the frame structure thereof being schematically shown inFIG. 31. As shown in the figure, “Control” is specified inCtype/response field of the message frame. PASS THROUGH is written tothe operation code and an operation identifier (here, command “mute”) iswritten to the operand.

[0253] Upon reception of the mute command supported by itself, the mediaplayer 31 as an AVRCP target returns an Accepted message indicative ofthe acceptance of the mute command to the media player 31 which is theAVRCP controller. In the piconet 30, the media player 31 is the masterdevice and the TV tuner 32 is a slave device, so that communicationbetween them is enabled.

[0254] For the transmission of this Accepted message, a PASS THROUGHcommand may be applied, the frame structure thereof being schematicallyshown in FIG. 32. As shown in the figure, “Accepted” is specified inCtype/response field of the message frame. PASS THROUGH is written tothe operation code and an operation identifier (here, command “mute”) iswritten to the operand.

[0255] Supplement:

[0256] The present invention has been described in detail with referenceto preferred embodiments. While the preferred embodiments of the presentinvention have been described using specific terms, such description isfor illustrative purposes only, and it is to be understood that changesand variations may be made without departing from the spirit or scope ofthe invention.

[0257] Herein, Bluetooth is used as the wireless communicationtechnology for example to perform remote control operations between theslave devices in a same piconet. The present invention is not restrictedto this wireless connection based on the Bluetooth technology. Forexample, the present invention is also applicable to wirelesscommunication technologies in which a master devices and its slavedevices are defined in a same piconet and data and commands areexchanged between these master and slave devices.

[0258] Essentially, the present invention is disclosed only in the formof examples and therefore the contents hereof should not be interpretedin a restrictive manner. In order to fully determine the spirit of thepresent invention, the claims appended hereto should be referenced.

INDUSTRIAL APPLICABILITY

[0259] As described and according to the invention, an excellentwireless communication apparatus, an excellent wireless communicationmethod, an excellent storage medium, and an excellent program areprovided for preferably exchanging the commands for device operationbetween devices connected in a wireless manner.

[0260] As described and according to the invention, an excellentwireless communication method, an excellent storage medium, and anexcellent program are provided for preferably exchanging the commandsfor device operation between slave devices in a piconet constituted byone master device and a plurality of slave devices as with Bluetooth.

[0261] As described and according to the invention, an excellentwireless communication method, an excellent storage medium, and anexcellent program are provided for preferably exchanging the commandsfor device operation between the two or more slave devices which can beconnected directly only to the master device in a piconet.

[0262] As described and according to the invention, an excellentwireless communication method, an excellent storage medium, and anexcellent program are provided which are capable of performing remotecontrol between the slave devices in a same piconet by use of theBluetooth remote control profile.

[0263] As described and according to the invention, an excellentwireless communication method, an excellent storage medium, and anexcellent program are provided which are capable of realizingcontrolling a slave device by another slave device via the master deviceby use of the conventional Bluetooth control profile such as AV RemoteControl Profile (AVRCP).

[0264] As described and according to the invention, by making the mostof the characteristics of the master and slave roles in Bluetoothwireless connection, the master device centrally manages the controlsfunctions supported by each slave device in a piconet, so that eachslave device can perform control between the slave devices in thepiconet without being aware of the other slave devices except the masterdevice.

[0265] The application in the master device called a system controllermanages the functions of the slave devices in a piconet, so that thecontrol profile implemented by each Bluetooth device may remainconventional. Namely, there is no need for newly creating a controlprofile or change the design thereof to embody the present invention, sothat existing Bluetooth devices may be used as slave devices withoutchange.

1. A wireless communication control apparatus for controlling, in acommunication cell of a type constituted by one master device and aplurality of slave devices in which each of said plurality of slavedevices is communicable only with said master device, a command exchangeoperation between the devices, comprising: controller/target inquirymeans for inquiring each device in said communication cell whether eachdevice operates as a controller or a target; support command inquirymeans for inquiring each device having a target function for a commandsupported thereby; and support command managing means for managing thecommands supported by each target device.
 2. The wireless communicationcontrol apparatus according to claim 1, wherein the master device andthe slave devices in said communication cell function as a controllerwhich issues commands and/or a target which supports the commands. 3.The wireless communication control apparatus according to claim 1 is themaster device which controls a communication condition in saidcommunication cell.
 4. The wireless communication control apparatusaccording to claim 1, wherein said wireless communication controlapparatus itself is capable of functioning as both the controller andthe target, and said support command managing means also manages supportcommands of said wireless communication control apparatus itselffunctioning as the target.
 5. The wireless communication controlapparatus according to claim 1, further comprising: command receivingmeans for receiving a command from the controller in said communicationcell; and command processing means for processing the received command.6. The wireless communication control apparatus according to claim 5,wherein said command processing means inquires said support commandmanaging means to transfer the received command to the target whichsupport said command.
 7. The wireless communication control apparatusaccording to claim 5, wherein said command processing means inquiressaid support command managing means and, if the received command issupported by the inquiring device, said inquiring device executes saidcommand.
 8. The wireless communication control apparatus according toclaim 5, wherein if there are at least two target devices which supportthe received command in said communication cell, said controller devicehas a function for specifying a particular target device and saidcommand processing means transfers said command to the specified targetdevice in accordance with the specification of the controller devicefrom which said command is transmitted.
 9. The wireless communicationcontrol apparatus according to claim 5, further comprising: receptionlog storage means for storing a reception log indicative of commandreception; and target identifying means for identifying a target whichexecutes the received command on the basis of the newest log stored insaid reception log storage means.
 10. The wireless communication controlapparatus according to claim 5, wherein, if there are at least twotarget devices which support the received command in said communicationcell, said command processing means transfers the received command toall target devices which support said command.
 11. A wirelesscommunication control method for controlling, in a communication cell ofa type constituted by one master device and a plurality of slave devicesin which each of said plurality of slave devices is communicable onlywith said master device, a command exchange operation between thedevices, comprising the steps of: inquiring each device in saidcommunication cell whether each device operates as a controller or atarget; inquiring each device having a target function for a commandsupported thereby; and managing the commands supported by each targetdevice.
 12. The wireless communication control method according to claim11, wherein the master device and the slave devices in saidcommunication cell function as a controller which issues commands and/ora target which supports the commands.
 13. The wireless communicationcontrol method according to claim 11 is a communication control methodin said master device for controlling a communication condition in saidcommunication cell.
 14. The wireless communication control methodaccording to claim 11 is a communication control method in said masterdevice capable of functioning as both the controller or the target and,in said support command managing step, the support command of saidmaster device itself is also managed.
 15. The wireless communicationcontrol method according to claim 11, further comprising the steps of:receiving a command from the controller in said communication cell; andprocessing the received command.
 16. The wireless communication controlmethod according to claim 15, wherein said command processing stepinquires each target in said communication cell for supported commandsto transfer the received command to the target which support saidcommand.
 17. The wireless communication control method according toclaim 15, wherein said command processing step inquires each target insaid communication cell for supported commands and, if the receivedcommand is found supported on the device which executes said wirelesscommunication control method, said received command is executed on saiddevice.
 18. The wireless communication control method according to claim15, further comprising the step of: if there are at least two targetdevices which support the received command in said communication cell,specifying a particular target device from said controller device, saidcommand processing step transferring said received command to the targetdevice specified by the controller device from which said command istransmitted.
 19. The wireless communication control method according toclaim 15, further comprising the steps of: storing a reception logindicative of command reception; and identifying a target which executesthe received command on the basis of the newest log stored in saidreception log storage step.
 20. The wireless communication controlmethod according to claim 15, wherein, if there are at least two targetdevices which support the received command in said communication cell,said command processing step transfers said received command to alltarget devices which support said received command.
 21. A wirelesscommunication control apparatus for controlling, in a piconet of aBluetooth wireless network constituted by one master device and aplurality of slave devices, at least one slave device in said piconethaving a controller function for issuing commands and at least one slavedevice having a target function for supporting commands, said masterdevice having both controller and target functions, comprising:connecting means for establishing Bluetooth communication in saidpiconet; controller/target function grasping means for grasping a slavedevice which functions as a target and/or a controller; and supportcommand grasping means for managing the commands supported by eachtarget in said piconet.
 22. The wireless communication control apparatusaccording to claim 21 is said master device which controls acommunication condition in said piconet.
 23. The wireless communicationcontrol apparatus according to claim 21, wherein said wirelesscommunication control apparatus operates as said master device whichcontrols a communication condition in said piconet and saidcontroller/target function grasping means lays a logical link (L2CAP)with each slave device in said piconet to inquire each slave device forits function by use of Service Discovery Protocol (SDP).
 24. Thewireless communication control apparatus according to claim 21, whereinsaid wireless communication control apparatus operates as said masterdevice which controls a communication condition in said piconet and saidsupport command grasping means lays a logical link (L2CAP) with eachslave device operating as the target in said piconet to inquire eachslave device for support commands by a method defined in an upperapplication protocol.
 25. The wireless communication control apparatusaccording to claim 21 operating as said master device for controlling acommunication condition in said piconet, further comprising: commandreceiving means for receiving a command, which is connected with theslave device operating as the controller in said piconet; and commandprocessing means for processing the received command.
 26. The wirelesscommunication control apparatus according to claim 25, wherein saidcommand processing means transfers the received command to the targetwhich support said received command.
 27. The wireless communicationcontrol apparatus according to claim 25, wherein said command processingmeans, if the received command is supported by itself, processes saidreceived command by itself.
 28. The wireless communication controlapparatus according to claim 25, wherein, if there are at least twotarget devices which support the received command in said piconet, saidcontroller device has a function for specifying a particular targetdevice and said command processing means transfers said command to thespecified target device in accordance with the specification of thecontroller device from which said command is transmitted.
 29. Thewireless communication control apparatus according to claim 25, furthercomprising: reception log storage means for storing a reception logindicative of command reception; and target identifying means foridentifying a target which executes the received command on the basis ofthe newest log stored in said reception log storage means.
 30. Thewireless communication control apparatus according to claim 25, wherein,if there are at least two target devices which support the receivedcommand in said piconet, said command processing means transfers thereceived command to all target devices which support said command.
 31. Awireless communication control method for controlling, in a piconet of aBluetooth wireless network constituted by one master device and aplurality of slave devices, at least one slave device in said piconethaving a controller function for issuing commands and at least one slavedevice having a target function for supporting commands, said masterdevice having both controller and target functions, comprising the stepsof: establishing Bluetooth communication in said piconet; grasping aslave device which functions as a target and/or a controller in saidpiconet; and managing the commands supported by each target in saidpiconet.
 32. The wireless communication control method according toclaim 31, wherein said wireless communication control method is realizedon said master device which controls a communication condition in saidpiconet.
 33. The wireless communication control method according toclaim 31, wherein said wireless communication control method is realizedon said master device which controls a communication condition in saidpiconet, wherein said controller/target function grasping step lays alogical link (L2CAP) with each slave device in said piconet to performfunction inquiry by use of Service Discovery Protocol (SDP).
 34. Thewireless communication control method according to claim 31, whereinsaid wireless communication control method is realized on said masterdevice which controls a communication condition in said piconet and saidsupport command grasping step lays a logical link (L2CAP) with eachslave device operating as the target in said piconet to inquire eachslave device for support commands by a method defined in an upperapplication protocol.
 35. The wireless communication control methodaccording to claim 31, wherein said wireless communication controlmethod is realized on said master device which controls a communicationcondition in said piconet, further comprising the steps of: receiving acommand, which is connected with the slave device operating as thecontroller in said piconet; and processing the received command.
 36. Thewireless communication control method according to claim 35, whereinsaid command processing step transfers the received command to thetarget which support said received command.
 37. The wirelesscommunication control method according to claim 35, wherein said commandprocessing step, if the received command is supported by said masterdevice, causes said master device itself to execute said command. 38.The wireless communication control method according to claim 35,wherein, if there are at least two target devices which support thereceived command in said piconet, further comprising the step of:specifying a particular target device; and said command processing steptransfers said command to the specified target device in accordance withthe specification of the controller device from which said command istransmitted.
 39. The wireless communication control method according toclaim 35, further comprising the steps of: storing a reception logindicative of command reception; and identifying a target which executesthe received command on the basis of the newest log stored in saidreception log storage step.
 40. The wireless communication controlmethod according to claim 35, wherein, if there are at least two targetdevices which support the received command in said communication cell,said command processing step transfers the received command to alltarget devices which support said command.
 41. storage medium physicallystoring computer software in a computer-readable form, said computersoftware being described so as to execute, on a computer system,wireless communication control for controlling command exchange betweendevices in a communication cell which is constituted by one masterdevice and a plurality of slave devices, each slave device being capableof communicating with only said master device, said computer softwarecomprising the steps of: inquiring each device in said communicationcell whether each device operates as a controller or a target; inquiringeach device having a target function for a command supported thereby;and managing the commands supported by each target device.
 42. A storagemedium physically storing computer software in a computer-readable form,said computer software being described so as to execute, on a computersystem, wireless communication control for controlling command exchangebetween devices in a piconet of a Bluetooth wireless network constitutedby one master device and a plurality of slave devices, at least one ofsaid plurality of slave devices in said piconet having a controllerfunction for issuing commands, at least one of the other slave deviceshaving a target function for supporting commands, and said master devicebeing capable of having both of said controller function and said targetfunction, said computer software comprising the steps of: establishingBluetooth communication in said piconet; grasping a slave device whichfunctions as a target and/or a controller; and managing the commandssupported by each target in said piconet.
 43. A computer program beingdescribed in a computer-readable form so as to execute, on a computersystem, wireless communication control for controlling command exchangebetween devices in a communication cell which is constituted by onemaster device and a plurality of slave devices, each slave device beingcapable of communicating with only said master device, said computersoftware comprising the steps of: inquiring each device in saidcommunication cell whether each device operates as a controller or atarget; inquiring each device having a target function for a commandsupported thereby; and managing the commands supported by each targetdevice.
 44. A computer program being described in a computer-readableform so as to execute, on a computer system, wireless communicationcontrol for controlling command exchange between devices in a piconet ofa Bluetooth wireless network constituted by one master device and aplurality of slave devices, at least one of said plurality of slavedevices in said piconet having a controller function for issuingcommands, at least one of the other slave devices having a targetfunction for supporting commands, and said master device being capableof having both of said controller function and said target function,said computer software comprising the steps of: establishing Bluetoothcommunication in said piconet; grasping a slave device which functionsas a target and/or a controller in said piconet; and managing thecommands supported by each target in said piconet.